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Holocene variations of wildfire occurrence as a guide for sustainable management of the northeastern Canadian boreal forest

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Forest Ecosystems 2015年第3期2卷 190-196页

作者： Ahmed El-Guellab hugo asselin Sylvie Gauthier Yves Bergeron Adam A.Ali NSERC/UQAT/UQàM Industrial Chair in Sustainable Forest Management Université du Québec en Abitibi-Témiscamingue Natural Resources Canada Canadian Forest Service – Laurentian Forestry Centre Centre for Bio-Archeology and Ecology (UMR5059 CNRS) Université Montpellier 2

Background: Cumulative impacts of wildfires and forest harvesting can cause shifts from closed-crown forest to open woodland in boreal ecosystems. To lower the probability of occurrence of such catastrophic regime shifts,forest logging must decrease when fire frequency increases, so that the combined disturbance rate does not exceed the Holocene maximum. Knowing how climate warming will affect fire regimes is thus crucial to sustainably manage the forest. This study aimed to provide a guide to determine sustainable forest harvesting levels, by reconstructing the Holocene fire history at the northern limit of commercial forestry in Quebec using charcoal particles preserved in lake ***: Sediment cores were sampled from four lakes located close to the northern limit of commercial forestry in Quebec. The cores were sliced into consecutive 0.5 cm thick subsamples from which 1 cm3 was extracted to count and measure charcoal particles larger than 150 microns. Age-depth models were obtained for each core based on accelerator mass spectroscopy(AMS) radiocarbon dates. Holocene fire histories were reconstructed by combining charcoal counts and age-depth models to obtain charcoal accumulation rates and, after statistical treatment,long-term trends in fire occurrence(expressed as number of fires per 1000 years).Results: Fire occurrence varied between the four studied sites, but fires generally occurred more often during warm and dry periods of the Holocene, especially during the Holocene Thermal Maximum(7000–3500 cal. BP), when fire occurrence was twice as high as at ***: The current fire regime in the study area is still within the natural range of variability observed over the Holocene. However, climatic conditions comparable to the Holocene Thermal Maximum could be reached within the next few decades, thus substantially reducing the amount of wood available to the forest industry.

关键词： Fire occurrence Holocene Boreal forest Northern li

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Stakeholder Perspectives on Use,Trade,and Conservation of Medicinal Plants in the Rasuwa District of Central Nepal

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Journal of Mountain Science 2011年第1期8卷 75-86页

作者： Yadav UPRETY Ram C.POUDEL hugo asselin Emmanuel K.BOON Krishna K.SHRESTHA Human Ecology Department Vrije Universiteit BrusselLaarbeeklaan 109B-1090 BrusselsBelgium Canada Research Chair in Aboriginal Forestry Université du Québec en Abitibi-Témiscamingue445Boulevard de l'UniversitéRouyn-NorandaQuébecJ9X 5E4Canada Kunming Institute of Botany Chinese Academy of Sciences Central Department of Botany Tribhuvan University

People's livelihood in several Himalayan regions largely depends on collection,use,and trade of medicinal *** use is generally not a problem,but commercial gathering of selected species to meet increasing national and international demand can result in *** management of medicinal plants requires a clear understanding of the respective roles,responsibilities and viewpoints of the various stakeholders *** personal interviews and group discussions,this study aimed at investigating the views of two stakeholder groups on use,trade and conservation of medicinal plants in the Rasuwa district of *** people and district and national organizations agreed that medicinal plants are collected for a combination of commercial and personal *** on market availability differed significantly:100 % of the respondents from district and national organizations saw markets as easily available,against only 36 % for local *** could explain why medicinal plants were perceived by local people to contribute less to income generation than to livelihood *** viewpoints were also expressed concerning the status of medicinal plants in the district:81 % of the respondents from district and national organizationsconsidered that medicinal plants were threatened,compared to only 28 % for local *** this disparity,both stakeholder groups agreed upon potential threats to medicinal plants:over-harvesting;habitat loss due to land-use change and deforestation;and over-grazing by *** challenges were identified regarding sustainable management of medicinal plants,such as ambiguous policies;lack of resources,information and infrastructures;habitat degradation;and *** these challenges,respondents agreed that the medicinal plants sector offers huge opportunities in the Rasuwa district,given resource availability,community awareness and motivation,and the priority given

关键词： Medicinal plants Livelihood improvement Income generation Himalaya Local people Conservation Policy

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